Bump starlette from 0.37.2 to 0.40.0 in /docs (#296)

Bumps [starlette](https://github.com/encode/starlette) from 0.37.2 to 0.40.0.
- [Release notes](https://github.com/encode/starlette/releases)
- [Changelog](https://github.com/encode/starlette/blob/master/docs/release-notes.md)
- [Commits](Kludex/starlette@0.37.2...0.40.0)

---
updated-dependencies:
- dependency-name: starlette
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

docs/requirements.txt

@@ -48,7 +48,7 @@ sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==1.0.7
 sphinxcontrib-serializinghtml==1.1.10
 phinxext-opengraph==0.9.1
-starlette==0.37.2
+starlette==0.40.0
 tomli==2.0.1
 typing-extensions==4.12.1
 urllib3==2.2.1